The mount doesn't have to be modified at all, only three screws on the focus ring have to be shifted. Tokina seems to have left some room for adjustment on purpose. If you do it properly and take your time, it shouldn't scratch the exterior of the lens body.

Thank you Peter. I was actually beginning to think the same thing the other day, that it might be best to get the camera in my hands before I decide on lenses. By that time it should be pretty clear what works and what doesn't. I really wanted the Tokina though..ha. Maybe I should switch and get the EF mount BMCC, still debating that one.

Christian Schmeer wrote:The mount doesn't have to be modified at all, only three screws on the focus ring have to be shifted. Tokina seems to have left some room for adjustment on purpose. If you do it properly and take your time, it shouldn't scratch the exterior of the lens body.

Great news if so Christian!! Nice work!

**Any post by me prior to Aug 2014 was before i started working for Blackmagic**

Christian Schmeer wrote:The mount doesn't have to be modified at all, only three screws on the focus ring have to be shifted. Tokina seems to have left some room for adjustment on purpose. If you do it properly and take your time, it shouldn't scratch the exterior of the lens body.

The mount doesn't have to be modified at all, only three screws on the focus ring have to be shifted. Tokina seems to have left some room for adjustment on purpose. If you do it properly and take your time, it shouldn't scratch the exterior of the lens body.

Could you Christian explain us the step by step DIY procedure. My mechanical skills are not that great ...

Really glad to read this. Was gonna part exchange it today to buy Nikon version with a decent adapter...sounds like Nikon users have same issues. Doing all that and finding same problem then reading this thread would have given me a nosebleed. Lol

Hi Christian,Well done, I know you are putting a blog tutorial together on how to do this.Patience is apparently a virtue but I have the lens in the same place you have it in photo and just wondering which screws you need to loosen/move? In the photo you have removed the recessed screw...Just wondering whether the other screws you move are the brass connectors to focus ring? Or the screws closer to zoom ring?Nice website too by the way.

Craig wrote:Hi Christian,Well done, I know you are putting a blog tutorial together on how to do this.Patience is apparently a virtue but I have the lens in the same place you have it in photo and just wondering which screws you need to loosen/move? In the photo you have removed the recessed screw...Just wondering whether the other screws you move are the brass connectors to focus ring? Or the screws closer to zoom ring?Nice website too by the way.

Edit..ok there are 3 of those recessed screws, do you mean those?

Craig

Hi Craig, there are 3 recessed screws. I removed them to be able to push the screw holes to the right, rotating an inner part of the lens (to right, holding the front of the lens forward). By default, the three screw holes were in the middle.

Craig wrote:Hi Christian,Well done, I know you are putting a blog tutorial together on how to do this.Patience is apparently a virtue but I have the lens in the same place you have it in photo and just wondering which screws you need to loosen/move? In the photo you have removed the recessed screw...Just wondering whether the other screws you move are the brass connectors to focus ring? Or the screws closer to zoom ring?Nice website too by the way.

Edit..ok there are 3 of those recessed screws, do you mean those?

Craig

Hi Craig, there are 3 recessed screws. I removed them to be able to push the screw holes to the right, rotating an inner part of the lens (to right, holding the front of the lens forward). By default, the three screw holes were in the middle.

Absolutely amazing. You guys rock. I think I noticed this during a shoot but just thought it was the LCD screen. I'll check when I get my own BMCC, which should be very soon. If it doesn't hit infinitely, Christian, I'm going to be looking out for your mod and applying that to my Tokina.

I have tried and tested this all day and I think all I have been doing is adjusting the infinity stop which does help a small amount but did not completely fix the issue.However I have the canon version and Christian has the Nikon.I really hope I have been doing something wrong.I look forward to Christian's blog.

i actually did this last night. just figured it out myself. it didn't work for me. i was hoping i did it wrong and the tutorial would reveal my mistake, but i did mine exactly like you said. i guess if your lens is just slightly out, this will work. in my case, my lens must have been too far off for this tiny adjustment to fix.

cheezweezl wrote:i actually did this last night. just figured it out myself. it didn't work for me. i was hoping i did it wrong and the tutorial would reveal my mistake, but i did mine exactly like you said. i guess if your lens is just slightly out, this will work. in my case, my lens must have been too far off for this tiny adjustment to fix.

Which version do you have, Canon or Nikon? My Nikon version was actually pretty badly out of focus and the effect of the modification was quite dramatic.

Pre-modification, using the Kiwifotos adapter, it was just plain unusable. Between 11-16mm at F/2.8 "infinity focus" went 5 meters max.

Pre-modification, using the Novoflex adapter, focus between 15-16mm at F/2.8 was fine, but between 11-14mm the focus only went up to about 50 meters.

Post-modification, using the Novoflex adapter, it now goes slightly beyond infinity focus between 12-16mm and just about reaches infinity focus at 11mm. 11mm F/2.8 is slightly soft, but not out of focus. I guess some softness at 11mm and wide open at F/2.8 is to be expected.

If anyone tries this modification, make sure to push the screw holes to the very right of the oval hole (front of the lens facing forward). Pushing them to the left worsens the infinity focus issue, as you're moving it closer, rather than further away.

Which version do you have, Canon or Nikon? My Nikon version was actually pretty badly out of focus and the effect of the modification was quite dramatic.

Pre-modification, using the Kiwifotos adapter, it was just plain unusable. Between 11-16mm at F/2.8 "infinity focus" went 5 meters max.

Pre-modification, using the Novoflex adapter, focus between 15-16mm at F/2.8 was fine, but between 11-14mm the focus only went up to about 50 meters.

Post-modification, using the Novoflex adapter, it now goes slightly beyond infinity focus between 12-16mm and just about reaches infinity focus at 11mm. 11mm F/2.8 is slightly soft, but not out of focus. I guess some softness at 11mm and wide open at F/2.8 is to be expected.

If anyone tries this modification, make sure to push the screw holes to the very right of the oval hole (front of the lens facing forward). Pushing them to the left worsens the infinity focus issue, as you're moving it closer, rather than further away.

i have the canon version. just thought of this, if focus is backwards on a nikon, would i have to push the screw hole to the left instead? if this is the case, i may be hosed anyway. the screw was already on the left, not in the middle like yours.

cheezweezl wrote:i have the canon version. just thought of this, if focus is backwards on a nikon, would i have to push the screw hole to the left instead? if this is the case, i may be hosed anyway. the screw was already on the left, not in the middle like yours.

This may the case actually since focus rings on Nikon lenses rotate the other way around. Try to get it as much as possible to the left hand side and see if it makes any difference.

cheezweezl,It might be that its only a Nikon fix. There are no reports of any Canon versions working, as far as I know. The Nikon version does, so it might be that Christian just got his working like all the other Nikons. Can anyone verify that they can fix infinity focus on the Canon version?

There's a couple of people i think at the BMC user forum that have reported success with the canon version, can't link to the thread because of the policy here but you should find it easy. Mixed reports so far though.

**Any post by me prior to Aug 2014 was before i started working for Blackmagic**

i moved mine back to the left and shoved it as far left as possible. it gets closer now when wide open. if i stop down to 5.6 or higher, it gets sharp at infinity. before i did anything, it took f8 to get sharp, so i guess there is an improvement.

on the other hand (and i will bring this up in my "flange distance" thread) i just found another lens that won't hit infinity, my canon 28mm f2.8. i'm starting to think there may be a flange distance problem with the camera.

I had the issue with a canon version of the lens. I moved the screws as far to the left as I could and it has improved it hugely (from virtually unusable at 11mm and wide open). The screws were very far to left when I first opened it. Thanks Christian!!

I had the issue with a canon version of the lens. I moved the screws as far to the left as I could and it has improved it hugely (from virtually unusable at 11mm and wide open). The screws were very far to left when I first opened it. Thanks Christian!!

cheers,

Scott

I'm glad it works on the Canon version as well, at least for some. One thing I don't like about the Tokina 11-16mm F/2.8 lens is that it seems to produce pronounced chromatic aberrations, which is well known about this lens. However, it seems to make moiré more apparent on the BMCC. Has anyone else noticed this?

I wish I had seen this before buying the Tokina 11-16... I have the infinity focus problem too.I'm gonna send it back but I wonder what ultra wide angle options we still have.For almost the same price, there is the Sigma 8-16 which seems nice, but is only 4.5 - 5.6.

Jeez... I'm glad I bought the Sigma 8-16 after reading this. Sure the Sigma is not so fast, but at least it works well for those wide outdoor shots. The only issue I really have with the Sigma is using my Heliopan Variable ND which does screw onto the front of the lens (with the extra removable part that the lens cap attaches to), but this does mean at 8mm, the is a fair bit of vignetting which does disappear at the 10mm mark which isn't the end of the world.

Such a shame there is so many problems with the Tokina, but I'm sure its only a matter of time before we start seeing some proper wide and fast lenses made especially for the BMCC EF mount.

Well have tried the fix this evening and dismantled my lens to adjust the screws, but no luck.Already adjusted over as far as they'll go. Guess that's the end of my Tokina on my BMCC. Works fine on my old DSLR.Mine's a Nikon mount and I'm using the Novaflex adapter.

Well I can also chime in on this EF version lens NOT infinity focusing on the BMCC.It focuses wonderfully on our 7D.

So will try the fix that has worked for some. But how do you access those screws?

OOPS! Finally found Christian's post reference to his step by step procedure on his blog. Sorry.Wondering how many have had success with this mod for the EF version.

It is difficult to understand how this lens performs on the 7D just fine, but not on the BMCC. Has to be a simple mechanical - distance function. Is there something different in the locked positioning of this particular lens that is slightly different than all the other lenses? Maybe there is something just slightly different in the Tokina to BMCC mount that does not allow the Tokina to match up exactly on the BMCC?

It cannot be optics or electronics... it is a mechanical match up difference.

Yea, I do wonder if it's the fit. My Tokina has a tiny bit of movement / play in its fit with the adapter that it doesn't have on my DSLR. And my plastic 35mm Nikon fits snug as bug with the adapter on the BMCC and is pin sharp. Compared to the Tokina it's way sharper through the entire focal range.But stick the Tokina on my DSLR and it's just as sharp. This gets weirder and weirder!

Ok- just got finished following the 3 screw adjustment noted on Christian's blog:This is an EF Canon Tokina 11-16:

- when first opened up to get to the 3 screws, found that you must move the 2 brass sleeved screws to move under the cover to gain access to ALL 3 screws.

- thought I would be in luck as all 3 screws were originally located to right of center in the ovals at the start (remember for Canons you want to adjust the location of these 3 screws as far left as you can get them to improve infinity focus; Nikons you want to move far right to improve infinity focus)

- after moving all 3 screws LEFT as far as cover would allow (one screw was starting to locate under the cover which would no longer allow tightening with a small jeweler's driver), the infinity focus was somewhat improved, but not perfect at 11mm as it is on the 7D.

- at 12mm I can get pretty good infinity focus

- at 13-16mm I get very good infinity focus

(all these were done at wide open 2.8 iris)

Unless it is something about the optics that I don't understand, I believe it is something in the machining of the Tokina EF mount that slightly throws off the flange distance on the BMCC. There is something in the way these two mount that isn't right. There appears to be some mechanical conflict unique to the Tokina/BMCC mounting match up.)

(I used Resolve and the Sizing feature to zoom into "1.500 to compare the same tripod located shots before and after adjustments.)

So until the full fix is found for this very popular and previously useful lens, here is what I recommend:

+ at 11mm stay way stopped down. Have not experimented how far down, but maybe 5.6 or more if you are trying for a landscape shot with deep depth of field

+ at 11mm for a CU with background thrown out of focus, you are good to go

+ for Infinity deep depth of field, stay 12mm to 16mm with closed down apertures - do your own experimentation - difficult in the field even with a quality SmallHD DP6 and sunhood.

Last edited by John Richard on Mon Feb 11, 2013 1:43 pm, edited 1 time in total.